Lawn mower



Dec. 3, 1929.

c. A. OLSON LAWN MowER Filed Aug. 29. 1928 Patented Dec. 3, 1929 CARL A; OLSON, OF CLARINDA, IOVA, ASSIGNOR T CLARINDA `LLLIQ'ITFACTlTRIIN'G COMn PANY, 0F GLARINDA, IOTNA, A CORPORATION 0F IWA LAWN MOWER Application led August 29, 192B. Serial No. 302,694.

The object of this invention is to provide an improvement in lawn mowers which consists in means for compensating tor wear at the central part of the stationary blade, so that the machine may be caused to continue to cut clean throughout the length of its cut ting mechanism.

A further object ol this invention is to provide a threaded adjusting member engaging the central portion oit the member which carries the stationary blade ot a lawn mower and arranged to draw the central portion ot the blade closer to the rotary reel to compensate for excessive wear at that part of the blade.

lWith these and other objects in if'iew my invention consists in the construction, arrangement and combination oilI the various parts of my device, whereby the objects contemplated are attained, as hereinafter more 'fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a plan view showing a portion of a lawn mower including my improvement.

Figure 2 is a cross-section on the line 2-2 ot Figure l, showing one form o'l' adjusting means.

Figure 3 is a view similar to Figure 2 and showing a different construction ot mower having a correspondingly diiiierent form oi adjusting means.

Figure l is a ci'oss-scctional view showing a still dillerent termoli mower with an adjusting means similar to that shown in Figure 3.

Figure `5 is an enlarged detail section ot the improvement according to the construction shown in Figure 2. i

Figure G is a similar showing yccording to the construction oi' Figure 3 or Figure at.

Vlhis invention relates to an improvement in that type of lawn mower in which. a rotary cutter or reel is employed to coact with a relatively stationary blade for cutting The stationary blade is usually mounted on member` called a bed bar, and adjusting screws are provided for tilting the bed bar to adjust the position ot the edge ot' the' blade relative to the orbit oit the reel. The adjusting screws usually are located at the ends of the bed bar.

It has been 'found that in the use ot a mower ol" this kind there is a greater wear at the central part ot the stationary blade than at its ends. ln other words, the wear is more or less in the torni oi a hollow curve longitudinally ont the blade, so that the central part ol the blade is not as close to the rotary cutter as the end portions, and hence the central part oi the mower does not cut as well or as closely. j

rlhis detect, ot course, cannot be overcome by manipulation of the usual adjusting screws, which tilt the bed bar bodily, or at either encL selectively.

is to overcome this difficulty that li have devised the present improvement, which consists ot a threaded member for springing the central part ot the bed bar more closely to the reel, enough to compensate for this entra wear at the center. This acts independently of the usual adjusting screws, or in addition to the adjustment secured by them.

ln the drawing l have employed the numerals l0 and ll to designate the wheels ot a lawn mower, and the numeral l2 to designate a rotary critter or reel mounted between and driven from said wheels.

The reel l2 is journaled inside trames i3 and lll, which are connectedat their 'forward ends by a cross rod l5 and at their rear ends by a ground roller i6. rlhere is also, in most mowers oit this type, an additional cross meinber such l? just forwardly et' the roller, which member is etten in the torni et a rod as here shown.,

The stationary knife l@ is mounted, as by screws '19, on a bed bar 2O and is arranged with its cuttingedge close tothe orbit of the reel l2. The proper positioning ot the bed bar and cutting edge ot the blade l@ is accomplished by means o'l: adjusting screws ill, usually mounted through ears on the side iframes and `suitably engaging the bed bar for adjustably supporting it and the lniiie.

ln the term ot mower shown in Figures 2 vand 3 there are two adjusting screws 2l at each side oi the mower, and they pass through apertured portions of the bed bar at their lower ends.

In the form of mower shown in Figure 4C av .single adjusting screw 21 is employed at each side of the mower, passing through an apertured arm 23 extending upwardly and rearwardly from each end of the bed bar. The lower ends of the screws 21 engage a clamping member 24 clamped to the cross member 17 and to the arms 23 by clamping bolts 25.

These different adjusting means form no part'of my present invention, butv are shown and described to illustrate the fact that my present improvement may be applied to mowers of different construction.

The bed bar is usually located close to a cross frame member such as the rod 17, and in most instances is hollowed out, grooved or in some manner -formed so as to partially embrace said member.

In Figures 2 and 5 the bed bar 2O is located below the cross rod 17 and in Figures 3, l and 6, it is located forwardly of and partially overhanging the rod, the overhanging part beingin the form of athin lip or iange 26. My improved adjusting and compensating means will have to assume different forms forV the different constructions of mowers `here shown, and possibly still diiferent forms for `still other constructions and arrangements of the bed bar or knife carrier relative toother parts of the mower.

In any event, my impovement is Aso designed as to apply pressure to the central part of the knife carrier to spring it and cause it to approach the orbit of the rotary knife Y the central part of the bed bar will be drawn up toward the cross member 17, and with it Y thecentral part of the blade 18 will be drawn Y up toward the reel.

As this is a springing action, the movement Y will. be greaterat the center where the bolt iis located,.and will taper toward both ends.

This is in accordance with the way the wear seems to occur, so that by this means the 'Y coacting cutting means may be caused to cut In certain views of the drawing, I have shown, in exaggerated form, the result of the action of the screw device in springing the blade carrying member to cause the blade to be bulged upwardly in its central portion to compensate for wear, and in this connection attention is directed particularly to Figures 5 and 6.

Some changes may be made in the construetion and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a lawn mower having a blade mounted on a blade carrying member fixed at its ends, said lawn mower having a frame member extending adjacent said blade carrying member, an adjusting means comprising a member engaging said frame member and an intermediate portion of said blade carrying member for springing the latter to compensate for wear at the central part of the blade.

2. In a lawn mower having a blade mounted on a blade carrying member adjustably supported at its ends, said lawn mower also having a frame member extending adjacent said blade carrying member, an auxiliary adjusting means comprising a threaded member engaging said frame member and an intermediate portion of said blade carrying .member for springing the latter to compensate for wear at the central part of the blade.

3. In a lawn mower having a blade lixed to a blade carrying member fixed at its ends, said lawn mower having a frame member au ranged substantially parallel with said blade carrying member, a compensating means comprising a threaded member having a connection with said frame member and having a portion engaging the central part of said blade carrying member, whereby tightening of said compensating member will result in a springing of the blade carrying member and blade to compensate for excessive wear at the central part of the blade.

Des Moines, Iowa, August 8, 1928.

CARL A. OLSON. 

